The subject is directed toward the art of metal removal cutting tools and, more particularly, to an improved drill capable of drilling from the solid in steel as well as, performing other single point metal removal operations such as boring, contouring and facing.
The invention is particular suited for embodiment in a structure which uses carbide inserts as the cutting element and will be described with reference thereto; however, the invention can be embodied in structures which use other materials or inserts as the cutting element.
Carbide has long been recognized as a particularly suitable material for use in cutting tools for metal removal operations. Most current uses of carbide for cutting involve the use of a tool support body or holder which carries one or more small carbide elements or inserts which define the cutting edges. These types of cutting tools have achieved widespread acceptance for a variety of operations including boring, milling, facing and contouring. However, attempts at using this general construction for tools capable of drilling steel or ferrous materials from the solid (as distinguished from enlarging a previously drilled hole) have not been particularly successful. Tools allegedly capable of performing this general function are shown in U.S. Pat. Nos. 3,422,706 to Lunsford and 3,540,323 to Rishel. The drills shown in these patents are for all intents single purpose and cannot perform other machining operations to the extent desirable.